BUDS PUBLIC SCHOOL, DUBAI
PHYSICS WORKSHEET
TOPIC- System of particle and rotational motion
Name:________________________
Class:11
Sec:___
Answer these questions:
1.
2.
3.
4.
5.
6.
7.
8.
Discuss the motion of centre of mass
Obtain the law of conservation of momentum of centre of mass.
Define torque. How it related to angular momentum
Define angular momentum of a rotating rigid body.
Obtain relation between torque and angular acceleration.
Define moment of inertia of a body about an axis.
Derive expression for kinetic energy of a rotating body.
Three bodies a ring, a solid cylinder and a solid sphere roll down an inclined plane
without slipping. They start from rest. The radii of the bodies are equal but may have
different masses. Which of the bodies reaches the ground with maximum velocity?
9. State and explain parallel axes and perpendicular axes theorems
10. Find the torque of a force 7i+3j-5k about the origin and the force acts on the particle whose
position vector is i-j+k
11. Moment of inertia of a thin rod of mass M and length l about an axis through the centre and
perpendicular to its length is (Ml2/12). What is its moment of inertia about an axis perpendicular
to its length and passing through one of its ends
12. Moment of inertia of a ring of mass M and radius r about any diameter is ½ Mr2. What is its
moment of inertia about an any tangent of the ring
13. The angular speed of a motor wheel is increased from 1200 rpm to 3210 rpm in 16
seconds. (a) What is its angular acceleration assuming it to be uniform? (b) How many
revolutions does the engine make during this time?
14. A cylinder of mass 5kg and radius 30cm free to rotate about its axis receives an angular
momentum impulse of 3kgm2/s initially, followed by similar impulse after every 4
seconds. What is the angular speed of the cylinder 30s after the initial impulse? The
cylinder is at rest initially.
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